Poured concrete floors have come into widespread use. In general, such floors comprise a cellular, fluted metal, or corrugated raceway floor deck over which a concrete slab is poured. The cellular metal deck or floor is provided with holes, usually pre-punched at the factory, through which access to electrical or communication lines installed within the cellular raceways of the floor can be had.
In the prior art, the connection of a floor outlet to the electrical or communiction system within the underfloor assembly has generally been accomplished by either of two relatively costly operations. In one prior art approach, an access box is preset into holes located on the top surface of the cellular metal floor. The concrete is then poured over the floor and box, leaving the top access portion of the box substantially exposed. In order to provide flexibility in the number and location of electrical and communication outlets, the need for which may vary substantially over a period of time, a large number of preset insert access boxes must be used, only a small number of which may actually be used. The large initial equipment cost necessary to provide these access boxes at numerous locations is a serious problem connected with the use of such a system.
The other general approach heretofore employed involves the use of so-called afterset inserts at the desired locations. In this method, no preset access boxes are used. Instead, the concrete floor is drilled or cored at the desired locations when necessary. While the use of afterset access boxes reduces the initial equipment cost, it has the disadvantage arising from the fact that concrete coring through the full thickness of the floor is a laborious and expensive operation. Moreover, when it is necessary to relocate outlets because of floor plan changes and the like, concrete coring causes a serious disruption in office operations.
The present invention provides an improved means and method for supplying electrical and communications outlets in poured concrete floors which overcome to a large extend the problems heretofore presented. While the invention involves the use of preset units, they are relatively inexpensive, thereby greatly reducing the high equipment cost of the preset method of floor installation. In addition, the invention eliminates the extensive coring operations and the consequent disruption of office procedures which havee heretofore characterized the use of afterset access boxes.